Implantable central venous catheters have been in use for several years and have many advantages for long-term venous access, particularly in cancer patients requiring chemotherapy and/or continuous doses of painkillers. The central location of the catheter tip in a high flow volume vein, such as a return vein to the heart, allows chemotherapeutic agents, which are toxic, to be quickly diluted by the high blood flow through the vein, minimizing local tissue damage and inflammation from the injected medicinal agent. However, needle puncture of the injection port is not necessarily easy or secure. In obese patients, the location or position of a port implanted close to the skin surface is frequently unstable because the implant is within the subcutaneous fat. If the injection port is placed in a more stable location in an obese patient, such as on the pectoral fascia, the port is then positioned far from the skin surface, making a successful injection of the port more difficult. In either situation, there is a risk of accidental subcutaneous infiltration of the agents because of the needle missing the injection port. Subcutaneous infiltration of chemotherapeutics, which are very toxic, can cause severe inflammation and necrosis of tissue. This can lead to severe complications and is especially detrimental to patients that are already debilitated and/or in fragile condition. Even when the needle tip position has been established by blood withdrawal prior to penetration of the injection port, there is no guarantee that the needle will stay in position within the port for the duration of the infusion of a chemotherapy agent and/or other medicinal agent.
It is an object of the present invention to provide a needle guide and support platform that can be readily positioned directly over the implanted injection port.
It is a further object of the present invention to provide a needle guide and support platform and implanted injection port that are mutually attracted to one another.
An even further object of the present invention is to provide an assembly that ensures the proper needle position and orientation with respect to the injection port through the mutual attraction by electro or permanent magnets or ferromagnetic bodies in the needle guide and support platform and ferromagnetic materials or permanent magnets in the implantable injection port to bring the assembly as close together as possible and to position and orient the needle with respect to the injection port, and to maintain the assembly in position during infusion.